This invention relates to a communication system, a communication method, a mobile station communicable with an object device, such as a video camera, a digital camera, and a computer-readable storage medium for use in the mobile station.
A mobile station, such as a mobile telephone or a portable telephone, was used only for voice communication through a base station. However, it has been a recent trend that data communication has also been realized by the use of such a mobile station. In order to establish the data communication by the use of a mobile station, a moving picture transmitter/receiver terminal (will be simply called a picture terminal hereinafter) has been developed and practically sold in a market. Such a picture terminal can be usually connected to the mobile station and can display, on a display unit, a moving picture sent from the base station through the mobile station. In any event, the picture terminal has been usually connected to the mobile station through physical connectors but might be connected to the mobile terminal through a wireless channel or through an infrared ray in the future. In this connection, the picture terminal will be called an object terminal that is operable as an object of the mobile station.
Herein, it is to be noted that a user or a possessor individually carries or bears the mobile station and the picture terminal and usually put them into operations independently of each other. This shows that, when the object terminal is called or accessed by the mobile station, the object terminal may not be always put into an active state and may not be always connected to the latter. Under the circumstances, when the moving picture is received by the mobile station, the user never knows that such a moving picture can not be received until the object device is taken out of his/her bag or the like. In other words, the user can not quickly confirm or make sure of status of the object device until the object device is taken out and the user recognizes the status of the object device. Accordingly, the user can not often receive or might uselessly lose the moving picture which is sent from the base station through the mobile station and which might be precious for the user.
Similar problems might occur even when the mobile station and the object device are connected to each other through a wireless channel or an infrared ray.
In Japanese Unexamined Patent Publication No. Hei 10-224859 (namely, JP-A 224859/1998) (will be referred to as Reference 1), description is made about data communication between mobile terminals or stations and an exchange. Specifically, it is assumed that one of the mobile stations is kept in an inactive state or an uncommunicable state when a sequence of data signal is transmitted from another mobile station. In this event, the data signal sequence is temporarily stored in an inside memory of the exchange. When the one mobile station is restored to a communicable state and makes sure of reception of the data signal sequence, a data transmission request is sent from the one mobile station to the exchange. In response to the data transmission request, the data signal sequence is transmitted from the inside memory of the exchange to the one mobile station. At any rate, the one mobile station can automatically access the exchange in the communicable state to receive the data signal sequence from the exchange.
In Japanese Unexamined Publication No. Hei 10-257558 (namely, JP-A 257558/1998) (will be referred to as Reference 2), description will be made about data communication between a main device and a subsidiary device. The main device includes a modem while the subsidiary device may be a personal computer. With this data communication, modem information is transmitted between the main and the subsidiary devices.
However, neither Reference 1 nor Reference 2 discloses data communication between a mobile station and an object device communicable with the mobile station.